Vulnerability of coastal ecosystems to changes in harmful algal bloom distribution in response to climate change: projections based on model analysis

Harmful algal blooms (HABs), those proliferations of algae that can cause fish kills, contaminate seafood with toxins, form unsightly scums, or detrimentally alter ecosystem function have been increasing in frequency, magnitude, and duration worldwide. Here, using a global modeling approach, we show, for three regions of the globe, the potential effects of nutrient loading and climate change for two HAB genera, pelagic Prorocentrum and Karenia, each with differing physiological characteristics for growth. The projections (end of century, 2090-2100) are based on climate change resulting from the A1B scenario of the Intergovernmental Panel on Climate Change Institut Pierre Simon Laplace Climate Model (IPCC, IPSL-CM4), applied in a coupled oceanographic-biogeochemical model, combined with a suite of assumed physiological 'rules' for genera-specific bloom development. Based on these models, an expansion in area and/or number of months annually conducive to development of these HABs along the NW European Shelf-Baltic Sea system and NE Asia was projected for both HAB genera, but no expansion (Prorocentrum spp.), or actual contraction in area and months conducive for blooms (Karenia spp.), was projected in the SE Asian domain. The implications of these projections, especially for Northern Europe, are shifts in vulnerability of coastal systems to HAB events, increased regional HAB impacts to aquaculture, increased risks to human health and ecosystems, and economic consequences of these events due to losses to fisheries and ecosystem services.

Biomass changes and trophic amplification of plankton in a warmer ocean

Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and regional models, imply the need for caution when extending these considerations into higher trophic levels.

Potential consequences of climate change for primary production and fish production in large marine ecosystems

Existing methods to predict the effects of climate change on the biomass and production of marine communities are predicated on modelling the interactions and dynamics of individual species, a very challenging approach when interactions and distributions are changing and little is known about the ecological mechanisms driving the responses of many species. An informative parallel approach is to develop size-based methods. These capture the properties of food webs that describe energy flux and production at a particular size, independent of species' ecology. We couple a physical–biogeochemical model with a dynamic, size-based food web model to predict the future effects of climate change on fish biomass and production in 11 large regional shelf seas, with and without fishing effects. Changes in potential fish production are shown to most strongly mirror changes in phytoplankton production. We project declines of 30–60% in potential fish production across some important areas of tropical shelf and upwelling seas, most notably in the eastern Indo-Pacific, the northern Humboldt and the North Canary Current. Conversely, in some areas of the high latitude shelf seas, the production of pelagic predators was projected to increase by 28–89%.

Marine Environment and Human Health: An Overview

The marine environment currently provides many beneficial goods and services to mankind but also poses a risk to the health of coastal populations. For example, toxic algal bloom events, microbial pathogens and pollutants all act to negatively impact human health mediated by the marine environment. At the same time, regular contact with the natural environment results in many health benefits, including increased fitness and reduced levels of stress. The marine environment is under pressure from land-derived contaminants and climate change, of which the socio-economic consequences and the implications for human health and wellbeing are not well understood. The scientific challenge is to understand and predict the consequences of environmental changes and exploitation of natural resources upon our coastal ecosystems and upon society, including human health. Addressing this challenge requires the integration of a wide range of disciplines, from physical oceanography and marine biology, to molecular biology and epidemiology.

Skill Assessment for Coupled Biological/Physical Models of Marine Systems

Coupled biological/physical models of marine systems serve many purposes including the synthesis of information, hypothesis generation, and as a tool for numerical experimentation. However, marine system models are increasingly used for prediction to support high-stakes decision-making. In such applications it is imperative that a rigorous model skill assessment is conducted so that the model's capabilities are tested and understood. Herein, we review several metrics and approaches useful to evaluate model skill. The definition of skill and the determination of the skill level necessary for a given application is context specific and no single metric is likely to reveal all aspects of model skill. Thus, we recommend the use of several metrics, in concert, to provide a more thorough appraisal. The routine application and presentation of rigorous skill assessment metrics will also serve the broader interests of the modeling community, ultimately resulting in improved forecasting abilities as well as helping us recognize our limitations.

Development of an expert system for the integration of biomarker responses in mussels into an animal health index

Biomarkers on sentinel organisms are utilised worldwide in biomonitoring programs. However, the lack of effective interpretational capacity has hampered their uptake for use for assessment of risk in environmental management. The aim of the present study was to develop and test an objective decision-support or expert system capable of integrating biomarker results into a five-level health-status index. The expert system is based on a set of rules derived from available data on responses to natural and contaminant-induced stress of marine mussels. Integration of parameters includes: level of biological organization; biological significance; mutual interrelationship; and qualitative trends in a stress gradient. The system was tested on a set of biomarker data obtained from the field and subsequently validated with data from previous studies. The results demonstrate that the expert system can effectively quantify the biological effects of different levels of pollution. The system represents a simple tool for risk assessment of the harmful impact of contaminants by providing a clear indication of the degree of stress syndrome induced by pollutants in mussels.

Lysosomal and autophagic reactions as predictive indicators of environmental impact in aquatic animals

The lysosomal-autophagic system appears to be a common target for many environmental pollutants as lysosomes accumulate many toxic metals and organic xenobiotics, which perturb normal function and damage the lysosomal membrane. In fact, lysosomal membrane integrity or stability appears to be an effective generic indicator of cellular well-being in eukaryotes: in bivalve molluscs and fish, stability is correlated with many toxicological responses and pathological reactions. Prognostic use of adverse lysosomal and autophagic reactions to environmental pollutants has been explored in relation to predicting cellular dysfunction and health in marine mussels, which are extensively used as sensitive bioindicators in monitoring ecosystem health. Derivation of explanatory frameworks for prediction of pollutant impact on health is a major goal; and we have developed a conceptual mechanistic model linking lysosomal damage and autophagic dysfunction with injury to cells and tissues. This model has also complemented the creation of a cell-based computational model for molluscan hepatopancreatic cells that simulates lysosomal, autophagic and other cellular reactions to pollutants. Experimental and simulated results have also indicated that nutritional deprivation-induced autophagy has a protective function against toxic effects mediated by reactive oxygen species (ROS). Finally, coupled measurement of lysosomal-autophagic reactions and modelling is proposed as a practical toolbox for predicting toxic environmental risk.

Lysosomal responses to nutritional and contaminant stress in mussel hepatopancreatic digestive cells: a modelling study

The lysosomal system occupies a central and crucial role in cellular food degradation (intracellular digestion), toxic responses and internal turnover (autophagy) of the hepatopancreatic digestive cell of the blue mussel Mytilus edulis. Understanding the dynamic response of this system requires factors affecting performance, conceived as a function of the throughput, degradative efficiency and lysosomal membrane stability, to be defined and quantified. A previous carbon/nitrogen flux model has been augmented by separately identifying lysosomal 'target' material (autophagocytosed or endocytosed proteins, carbohydrates and lipids) and 'internal' material (digestive enzymes and lipid membrane components). Additionally, the whole cell's energetic costs for maintaining lysosomal pH and production of these internal components have been incorporated, as has the potentially harmful effect of generation of lipofuscin on the transitory and semi-permanent lysosomal constituents. Inclusion of the three classes of nutrient organic compounds at the whole cell level allows for greater range in the simulated response, including deamination of amino acids to provide molecules as a source of energy, as well as controlling nitrogen and carbon concentrations in the cytosol. Coupled with a more functional framework of pollutant driven reactive oxygen species (ROS) production and antioxidant defence, the separate and combined effects of three stressors (nutritional quality, nutrient quantity and a polycyclic aromatic hydrocarbon [PAH-phenanthrene]) on the digestive cell are simulated and compare favourably with real data.

Autophagy: role in surviving environmental stress

This conceptual paper addresses the role of lysosomal autophagy in cellular defence against oxidative stress. A hypothesis is proposed that autophagic removal of oxidatively damaged organelles and proteins provides a second tier of defence against oxidative stress. Age pigment or lipofuscin is a product of oxidative attack on proteins and lipids and can accumulate in lysosomes, where it can generate reactive oxygen species (ROS) and inhibit lysosomal function, resulting in autophagic failure. It is further hypothesised that repeated triggering of augmented autophagy can protectively minimise lipofuscin generation; and that animals living in fluctuating environments, where autophagy is repeatedly stimulated by natural stressors, will be generically more tolerant of pollutant stress. Data for resistance to pollutant stress is presented, together with evidence for a correlation between lysosomal stability and macrobenthic diversity. Finally, we speculate that organisms making up functional ecological assemblages in fluctuating environments, where up-regulation of autophagy should provide a selective advantage, may be pre-selected to be tolerant of pollutant-induced oxidative stress.

Environmental prognostics: an integrated model supporting lysosomal stress responses as predictive biomarkers of animal health status

The potential prognostic use of lysosomal reactions to environmental pollutants is explored in relation to predicting animal health in marine mussels, based on diagnostic biomarker data. Cellular lysosomes are already known to accumulate many metals and organic xenobiotics and the lysosomal accumulation of the carcinogenic polycyclic aromatic hydrocarbon 3-methylcholanthrene (3-MC) is demonstrated here in the hepatopancreatic digestive cells and ovarian oocytes of the blue mussel. Lysosomal membrane integrity or stability appears to be a generic indicator of cellular well-being in eukaryotes; and in bivalve molluscs it is correlated with total oxygen and nitrogen radical scavenging capacity (TOSC), protein synthesis, scope for growth and larval viability; and inversely correlated with DNA damage (micronuclei), as well as lysosomal swelling (volume density), lipidosis and lipofuscinosis, which are all characteristic of failed or incomplete autophagy. Integration of multiple biomarker data is achieved using multivariate statistics and then mapped onto "health status space" by using lysosomal membrane stability as a measure of cellular well-being. This is viewed as a crucial step towards the derivation of explanatory frameworks for prediction of pollutant impact on animal health; and has facilitated the development of a conceptual mechanistic model linking lysosomal damage and autophagic dysfunction with injury to cells, tissues and the whole animal. This model has also complemented the creation and use of a cell-based bioenergetic computational model of molluscan hepatopancreatic cells that simulates lysosomal and cellular reactions to pollutants. More speculatively, the use of coupled empirical measurements of biomarker reactions and modelling is proposed as a practical approach to the development of an operational toolbox for predicting the health of the environment.

Diagnostic monitoring of a changing environment: an alternative UK perspective

Adaptive management of the marine environment requires an understanding of the complex interactions within it. Establishing levels of natural variability within and between marine ecosystems is a necessary prerequisite to this process and requires a monitoring programme which takes account of the issues of time, space and scale. In this paper, we argue that an ecosystem approach to managing the marine environment should take direct account of climate change indicators at a regional level if it is to cope with the unprecedented change expected as a result of human impacts on the earth climate system. We discuss the purpose of environmental monitoring and the importance of maintaining long-term time series. Recommendations are made on the use of these data in conjunction with modern extrapolation and integration tools (e.g. ecosystem models, remote sensing) to provide a diagnostic approach to the management of marine ecosystems, based on adaptive indicators and dynamic baselines.

Towards computational models of cells for environmental toxicology

This paper outlines an approach to the development of computational models of cells for marine environmental toxicology. Exposure of cells to pollutants can lead to lysosomal damage and dysfunction, augmented autophagy, cellular dysfunction and atrophy and ultimately tissue pathology and organ damage. The application of carbon and nitrogen based models of intra cellular vesicular traffic for simulating the autophagic and lysosomal response of the hepatopancreatic digestive cells of marine molluscs is described. Two numerical models of the vesicular transport of carbon and nitrogen in the cell are presented. These demonstrate the importance of endocytotic uptake as a driver of lysosomal dynamics and the need to recognize and model it as a discrete process. Conceptual and mathematical models of the toxic impact of polycyclic aromatic hydrocarbons on the digestive gland are presented. The role of experimental research and the need to integrate it with modelling is highlighted.

A carbon and nitrogen flux model of mussel digestive gland epithelial cells and their simulated response to pollutants

The mussel digestive gland epithelial cells provide a key interface between the organism and pollutants such as aromatic hydrocarbons. The simulation of their uptake and export mechanisms as well as an internal protein degradation pathway, and any subsequent disruption to any of them, has been undertaken. A computational model is described, which simulates the flow of carbon and nitrogen through a mussel's digestive cell. The model uses a compartmentalised view of the cell with inviolate 'pipelines' connecting each of the volume-variable partitions. Only the major physiological pathways relevant to the flow of either carbon or nitrogen or volume are modelled. Simulated response to hydrocarbon exposure is examined.

Environmental prognostics: is the current use of biomarkers appropriate for environmental risk evaluation?

Environmental Prognostics is proposed as an integrated explanatory framework for adverse changes in whole systems, from cells to animals to ecosystems. The aim is to develop such frameworks for the evaluation of "health of the environment" and prediction of consequences resulting from future environmental events based on integrating the reactions of biomarkers for cellular and physiological processes, through conceptual, statistical and computational modelling. These are urgently needed to synthesise complex information on environmental chemistry and injurious effects of pollutants into predicted harmful impact on health of sentinel animals.

Nutrient fluxes and budgets for the North West European Shelf from a three-dimensional model

A three-dimensional ecosystem model of the NW European continental shelf is used to simulate the seasonal cycle of nutrients (N, P, Si) and primary and secondary production during 1995. Nutrient budgets within areas of the shelf are calculated and their component parts (advective, benthic, pelagic, riverine, recycling) are examined. Nutrient fluxes across sections of the continental shelf are also calculated and compared with previous modelled/observed flux values.

A computational model of the digestive gland epithelial cell of marine mussels and its simulated responses to oil-derived aromatic hydrocarbons

This paper describes a computational model of digestive gland epithelial cells (digestive cells) of marine mussels. These cells are the major environmental interface for uptake of contaminants, particularly those associated with natural particulates that are filtered from seawater by mussels. Digestive cells show well characterised reactions to exposure to lipophilic xenobiotics, such as oil-derived aromatic hydrocarbons (AHs), which accumulate in these cells with minimal biotransformation. The simulation model is based on processes associated with the flux of carbon through the cell. Physiological parameters such as fluctuating food concentration, cell volume, respiration, secretion/excretion, storage of glycogen and lipid, protein/organelle turnover (autophagy/resynthesis) and export of carbon to other tissues of the mussel are all included in the model. The major response to AHs is induction of increased autophagy in these cells. Simulations indicate that the reactions to AHs and food deprivation correspond well with responses measured in vivo.

Extraction of a weak climatic signal by an ecosystem

The complexity of ecosystems can cause subtle and chaotic responses to changes in external forcing. Although ecosystems may not normally behave chaotically, sensitivity to external influences associated with nonlinearity can lead to amplification of climatic signals. Strong correlations between an El Niño index and rainfall and maize yield in Zimbabwe have been demonstrated; the correlation with maize yield was stronger than that with rainfall. A second example is the 100,000-year ice-age cycle, which may arise from a weak cycle in radiation through its influence on the concentration of atmospheric CO2 (ref. 5). Such integration of a weak climatic signal has yet to be demonstrated in a realistic theoretical system. Here we use a particular climatic phenomenon-the observed association between plankton populations around the UK and the position of the Gulf Stream-as a probe to demonstrate how a detailed marine ecosystem model extracts a weak signal that is spread across different meteorological variables. Biological systems may therefore respond to climatic signals other than those that dominate the driving variables.

Emergency upper gastrointestinal bleeding. Management and outcomes in specialty private practice

Severe upper gastrointestinal (UGI) bleeding is a common medical emergency associated with significant morbidity and mortality. Recent studies from selected academic medical centers show that emergency UGI endoscopy with therapeutic intervention prevents recurrent hemorrhage, reduces complications, and limits costs. We determined prospective outcomes for patients presenting to 11 hospitals in Minneapolis and treated by 17 gastroenterologists from an independent single-specialty group. All 291 patients with severe UGI bleeding seen from July 1994 to January 1995 were enrolled and treated according to a guideline that the gastroenterologists had previously agreed upon. Chart review after hospital discharge showed that therapeutic endoscopy resulted in substantial reductions in the risk of recurrent bleeding compared with recent historic controls; the reductions were comparable to those seen in randomized studies from academic centers. Low risk of recurrent bleeding was associated with fewer blood transfusions and fewer days in hospital and in ICU. We conclude that 1) committed specialists can develop and adhere to treatment plans that optimize patient benefit and limit costs, and 2) therapeutic endoscopy performed by gastroenterologists in community hospitals may be as effective as endoscopy performed by academicians with a special interest in UGI bleeding.

Molecular biology of colon polyps and colon cancer

From a histologic and endoscopic standpoint, colon and rectal cancer (CRC) begins as a small neoplastic polyp which progressively enlarges and transforms through a dysplasia stage into invasive cancer. Recently, molecular abnormalities underlying the adenomacarcinoma progression have been defined. The adenomatous polyposis coli (APC) gene and mismatch repair genes are found to be dysfunctional early in the neoplastic process; either as inherited or somatic mutations. Subsequently, polyps progress to cancer along one of two paths depending on which gene is abnormal. When the APC gene is the initial mutation tumor development follows the "loss of heterozygocity" (LOH) pathway. If mismatch repair genes are altered, the "replication error" (RER) pathway is followed. Somatic mutations of the K-ras oncogene and the MCC, DCC, and p53 tumor suppressor genes accumulate in the LOH pathway and mark the progression through polyp stages. Microsatellite instability is a characteristic of the RER pathway but the precise genes involved in this pathway currently are not known. Defining these pathways has led to a new classification scheme for CRC with resultant changes in our clinical approach to screening, surveillance, and treatment.

Protein energy malnutrition in severe alcoholic hepatitis: diagnosis and response to treatment. The VA Cooperative Study Group #275

BACKGROUND

Active nutrition therapy and the anabolic steroid oxandrolone (OX), in selected patients with severe alcoholic hepatitis, significantly improved liver status and survival. We report here on the changes in their nutritional parameters.

METHODS

Protein energy malnutrition (PEM) was evaluated and expressed as percent of low normal in 271 patients initially, at 1 month and at 3 months. Active therapy consisted of OX plus a high caloric food supplement vs a matching placebo and a low calorie supplement.

RESULTS

PEM was present in every patient; mean PEM score 60% of low normal. Most of the parameters improved significantly from baseline on standard care; the largest improvement seen in visceral proteins, the smallest in fat stores (skinfold thickness). Total PEM score significantly correlated with 6 month mortality (p = .0012). Using logistic regression analysis, creatinine height index, hand grip strength and total peripheral blood lymphocytes were the best risk factors for survival. When CD lymphocyte subsets replaced total lymphocyte counts in the equation, CD8 levels became a significant risk factor (p = .004). Active treatment produced significant risk factor (p = .004). Active treatment produced significant improvements in those parameters related to total body and muscle mass (ie, mid arm muscle area, p = .02; creatinine height index, p = .03; percent ideal body weight, p = .04).

CONCLUSION

Deterioration in nutritional parameters is a significant risk factor for survival in severe patients with alcoholic hepatitis. This deterioration is reversible with standard hospital care. Active therapy further improves creatinine height index, mid arm muscle area and total lymphocyte counts. Hence, these later parameters appear to be the best indicators for follow-up assessments.

The role of tumor necrosis factor-alpha in acute endotoxin-induced hepatotoxicity in ethanol-fed rats

An in vivo model of ethanol ingestion in rats was used to examine tumor necrosis factor-alpha production after intravenous injection with lipopolysaccharide or saline solution. Four groups of 125-gm male Sprague-Dawley rats were given one of the following four diets: liquid ethanol diet (ethanol, 36% of calories), liquid control diet, chow ad libitum or control liquid diet pair-fed to match calories consumed by ethanol-fed rats. After 6 wk of diet, all rats were injected with 1 mg/kg lipopolysaccharide or 0.9% saline. AST concentrations in the ethanol-lipopolysaccharide group (388 +/- 54 U/ml) were significantly increased compared with those in control-saline, ethanol-saline and control-lipopolysaccharide groups (166 +/- 23, 166 +/- 18, 219 +/- 47; p < 0.01). Serum tumor necrosis factor-alpha concentrations for the ethanol-LPS group (3,990 +/- 624 pg/ml) were increased compared with those in control-saline (87 +/- 18), ethanol-saline (68 +/- 24) and control-LPS (695 +/- 165) groups (p < 0.001). A strong correlation was seen between serum tumor necrosis factor-alpha and AST concentrations (r = 0.91, p < 0.001). Treatment with lipopolysaccharide also increased transcriptional levels of tumor necrosis factor-alpha-specific mRNA from hepatic Kupffer cells isolated from rats fed the long-term ethanol diet by a factor of 3 compared with control rats. From these data, we conclude that long-term ethanol administration sensitized hepatic Kupffer cells to secrete high levels of tumor necrosis factor-alpha after lipopolysaccharide injection. Increased serum tumor necrosis factor-alpha concentrations correlated directly with increased levels of serum transaminase, which may have reflected hepatic injury.

A study of oral nutritional support with oxandrolone in malnourished patients with alcoholic hepatitis: results of a Department of Veterans Affairs cooperative study

A Veterans Affairs cooperative study involving 273 male patients was performed to evaluate efficacy of oxandrolone in combination with an enteral food supplement in severe alcoholic hepatitis. All patients had some degree of protein calorie malnutrition. On an intention-to-treat basis, only minimal changes in mortality were observed. However, in patients with moderate malnutrition mortality on active treatment at 1 mo was 9.4% compared with 20.9% in patients receiving placebo. This beneficial effect was maintained so that after 6 mo on active treatment 79.7% of patients were still alive, compared with 62.7% of placebo-treated patients (p = 0.037). Improvements in both the severity of the liver injury (p = 0.03) and malnutrition (p = 0.05) also occurred. No significant improvement was observed with severe malnutrition. To better determine the effect on therapeutic efficacy, we compared results with those from a nearly identical population (cooperative study 119) treated with oxandrolone but not given the food supplement. Patients were stratified according to their caloric intake (greater than 2,500 kcal/day was considered adequate to supply energy needs and promote anabolism). For patients with moderate malnutrition and adequate caloric intake, oxandrolone treatment reduced 6-mo mortality (4% active treatment vs. 28% placebo [p = 0.002]). For patients with moderate malnutrition and inadequate calorie intake, oxandrolone had no effect on mortality (30% active treatment vs. 33% placebo). In cases of severe malnutrition, oxandrolone had no effect on survival. However, adequate caloric intake was associated with 19% mortality, whereas patients with inadequate intake exhibited 51% mortality (p = 0.0001). These results indicate that nutritional status should be evaluated in patients with alcoholic hepatitis. When malnutrition is present, vigorous nutrition therapy should be provided, and in patients with moderate malnutrition oxandrolone should be added to the regimen.

Circulating tumor necrosis factor, interleukin-1 and interleukin-6 concentrations in chronic alcoholic patients

Although altered cytokine homeostasis has been implicated in the pathogenesis of alcoholic liver disease, the relationship between cytokines and metabolic consequences of alcoholic liver disease is unknown. We, therefore, sought to correlate circulating concentrations of tumor necrosis factor-alpha, interleukin-1 and interleukin-6 to clinical and biochemical parameters of liver disease in chronic alcoholic patients. We used an enzyme-linked immunosorbent assay to measure plasma tumor necrosis factor and interleukin-1 and a bioassay to measure serum interleukin-6 in three groups of alcoholic men as follows: (a) actively drinking alcoholic men without evidence of chronic liver disease, (b) nondrinking alcoholic men with stable cirrhosis and (c) patients with acute alcoholic hepatitis. Mean cytokine concentrations were elevated in cirrhotic patients and alcoholic hepatitis patients compared with controls and alcoholic patients without liver disease. Tumor necrosis factor-alpha and interleukin-1 alpha concentrations remained elevated for up to 6 mo after diagnosis of alcoholic hepatitis, whereas interleukin-6 normalized in parallel with clinical recovery. Concentrations of all three cytokines were correlated with biochemical parameters of liver injury and hepatic protein synthesis plus serum immunoglobulin concentrations. We could not demonstrate a relationship between cytokine concentrations and peripheral endotoxemia. Percentages of peripheral blood monocytes that reacted with monoclonal antibodies to CD25 (interleukin-2 receptor) and human lymphocyte antigen-DR were similar for alcoholic patients and controls. These data suggest that tumor necrosis factor-alpha and interleukin-1 alpha are related to some of the metabolic consequences of both acute and chronic alcohol-induced liver disease, whereas interleukin-6 is related to abnormalities seen in acute liver injury.

Interaction between endogenous opioids and IL-2 on PHA-stimulated human lymphocytes

Endogenous opioids exert a variety of extra central nervous system (CNS) functions, including modulation of some human lymphocyte functions. The latter opioid activity may result in elevation of human natural killer (NK) function (i.e. by beta-endorphin), which is reversed by an opioid antagonist, Naloxone. Since recent evidence has suggested both structural and functional similarities between lymphokines known to elevate human NK function (interferon and interleukin-2) and endogenous opioids, we investigated if Naloxone could modulate lymphokine-enhanced human NK activity. Naloxone blunted, in a dose-dependent fashion, the NK-enhancing activity of peripheral blood lymphocytes or large granular lymphocytes by recombinant interferon-alpha (IFN-alpha) or interleukin-2 (IL-2). Naloxone decreased the uptake of radiolabelled IL-2 receptors. beta-endorphin also decreased the binding of radiolabelled IL-2 or IL-2 receptor-positive human lymphocytes. Finally, labelled Naloxone was inhibited from binding to phytohaemagglutinin (PHA)-stimulated lymphocytes by either beta-endorphin or IL-2. These findings strongly suggest that human lymphocyte receptors for opioid, IFN or IL-2 molecules, once occupied, have distinct influences on the alternate receptor. In addition, these data further strengthen the potential role of CNS-mediated influences on the human immune system.

Peritoneovenous shunting as compared with medical treatment in patients with alcoholic cirrhosis and massive ascites. Veterans Administration Cooperative Study on Treatment of Alcoholic Cirrhosis with Ascites

The optimal management of severe ascites in patients with alcoholic cirrhosis has not been defined. in a 5 1/2-year study, we randomly assigned 299 men with alcoholic cirrhosis, who had persistent or recurrent severe ascites despite a standard medical regimen, to receive either intensive medical treatment or peritoneovenous (LeVeen) shunting. We identified three risk groups: Group 1 had normal or mildly abnormal results on liver-function tests, Group 2 had more severe liver dysfunction or previous complications, and Group 3 had severe prerenal azotemia without kidney disease. For the patients who received the medical treatment and those who received the surgical treatment combined, the median survival times were 1093 days in Group 1, 222 days in Group 2, and 37 days in Group 3 (P less than or equal to 0.01) for all comparisons). For all the groups combined, the median time to the resolution of ascites was 5.4 weeks for medical patients and 3.0 weeks for surgical patients (P less than 0.01). Within each risk group, mortality during the initial hospitalization and median long-term survival were similar among patients receiving either treatment. However, the median time to the recurrence of ascites in Group 1 was 4 months in medical patients, as compared with 18 months in surgical patients (P = 0.01); in Group 2 it was 3 months in medical patients as compared with 12 months in surgical patients (P = 0.04). The median duration of hospitalization was longer in medical patients than in surgical patients (6.1 vs. 2.4 weeks in Group 1 [P less than 0.001] and 5.0 vs. 3.1 weeks in Group 2 [P less than 0.01]). Group 3 was too small to permit a meaningful comparison. During the initial hospitalization, the incidence of infections, gastrointestinal bleeding, and encephalopathy was similar among the medical and surgical patients. We conclude that peritoneovenous shunting alleviated disabling ascites more rapidly than medical management. However, survival was closely related to the severity of the illness at the time of randomization and was not altered by shunting.

Accumulation of colony-stimulating factor 1 in amniotic fluid during human pregnancy

Colony-stimulating factor 1 is a hematopoietic growth factor that increases 1000-fold in the uteri of pregnant mice, and its receptor is abundantly expressed in the human placenta. The concentration of colony-stimulating factor 1 in amniotic fluid at 33 to 40 weeks (9.0 +/- 1.1 ng/ml) was twofold higher than that at 16 to 18 weeks gestation (4.1 +/- 0.5 ng/ml), whereas maternal serum colony-stimulating factor 1 levels did not rise significantly. Colony-stimulating factor 1 was detected in endometrial extracts from pregnant women and levels were higher than those in extracts from nonpregnant women.

Detection of endogenous macrophage colony-stimulating factor (M-CSF) in human blood

We have detected endogenous human macrophage colony-stimulating factor (M-CSF) in blood of normal individuals, using a novel RIA that accurately measures M-CSF concentrations as low as 60 U/ml (1.2 ng/ml) in the presence of serum proteins. The RIA uses an antibody to highly purified recombinant human M-CSF and is calibrated to a mouse bone marrow colony-forming assay. Ten samples of normal human blood plasma contained an average 118 +/- 9 U/ml of M-CSF, and similar concentrations were detected in serum prepared from the same individuals. RIA-positive samples contained biologically active M-CSF, as determined in a colony assay performed on mouse bone marrow cells. The M-CSF biological activity was removed by specific immune precipitation and inhibited by addition of M-CSF antibody. Physical characterization of plasma M-CSF was done by immunoblotting after partial purification on controlled pore glass and immunoaffinity chromatography. The major reduced protein species of plasma M-CSF had an apparent molecular weight of about 24 kd, and minor species of 30, 45, and 60-70 kd were also present. The RIA results on ten normal individuals suggest that endogenous circulating M-CSF is present at a low but detectable concentration. This RIA can be used to measure M-CSF in clinical samples that contain serum proteins and other growth factors that may interfere with accurate bioassay determinations.

Opiate antagonist nalmefene inhibits ethanol-induced flushing in Asians: a preliminary study

Ethanol-induced flushing (EIF) occurs in up to 80% of Asians and is characterized by facial flushing, tachycardia, and increased cardiac output. Since endogenous opiates and prostaglandins may be mediators of flushing syndromes, we attempted to block EIF in four Asian flushers with single doses of either the opiate antagonist nalmefene, or the prostaglandin synthesis inhibitor indomethacin. Nonflushers (2 Caucasian, 2 Asian) and four Asian flushers were given on separate days water, ethanol (0.4 g/kg p.o.), ethanol plus nalmefene (2 mg i.v.), or ethanol plus indomethacin (50 mg p.o.). Ethanol concentrations of flushers and nonflushers were similar. Mean (+/- SEM) plasma acetaldehyde concentrations of flushers (28.2 +/- 11.8 microM) were significantly greater than nonflushers (1.4 +/- 0.5 microM) following ethanol ingestion (p less than 0.001). Ethanol alone always induced a significant rise in facial skin temperature [mean area under the curve (AUC) = 5142 +/- 648 % delta T x min, p less than 0.01] and of pulse (mean AUC = 1622 +/- 120 bpm x min, p less than 0.001) in flushers compared to water ingestion. A single dose of nalmefene (2 mg i.v.) but not indomethacin (50 mg p.o.), reduced the mean (+/- SEM) ethanol-induced rise in facial skin temperature of flushers by 58 +/- 14% (p less than 0.05) without changing plasma acetaldehyde concentrations. These data are preliminary evidence that the opiate antagonist, nalmefene, blocks some of the vascular manifestations of EIF without altering the elevated plasma concentrations of acetaldehyde.

Cimetidine modulates natural killer cell function of patients with chronic lymphocytic leukemia

Peripheral blood natural killer (NK) activity in patients with B-cell chronic lymphocytic leukemia (B-CLL) is frequently low or absent. Because cimetidine (a histamine-2 antagonist) has been shown to alter human lymphocyte function in vitro, we decided to study cimetidine's effect on peripheral blood NK activity of patients with B-CLL and controls. We administered cimetidine orally (1.2 gm per day) to seven patients with B-CLL and 12 controls for up to 28 days. Peripheral blood NK activity of patients with B-CLL rose from a pretreatment level of 0.7 +/- 0.5 (mean +/- SEM) lytic units/10(6) cells (LU) to 8.7 +/- 2.4 LU (P less than 0.05) at day 28. Peripheral blood NK activity of controls decreased after 14 days of cimetidine treatment but returned to pretreatment levels by day 28. When peripheral blood cells from controls were exposed to cimetidine during in vitro incubation (10 micrograms/ml), mean NK activity was increased at 48 hours (54% +/- 22% increase over controls, n = 5, P less than 0.05). Single cell cytotoxicity assays revealed increased killing of target cells (but not effector-target conjugation) with cimetidine-exposed effector cells. These data suggest that cimetidine may be useful to augment peripheral blood NK activity for patients with B-CLL.

Pseudomonas infection of the biliary system resulting from use of a contaminated endoscope

Pseudomonas aeruginosa was present in bile cultures from 10 patients who had undergone previous endoscopic retrograde cholangiopancreatography in 1984. After environmental cultures and review of instrument disinfection, we traced the infections to a single endoscope contaminated with P. aeruginosa, serotype 10. Although the instrument had been cleaned repeatedly with an automatic endoscope cleaning machine, P. aeruginosa survived on residual moisture left in the channels of the endoscope. Contamination ended only after we began to manually suction alcohol through the endoscope before air drying. In 5 of 10 patients, P. aeruginosa caused clinical infections including gangrenous cholecystitis, abscesses, and death. We could identify no factor that distinguished symptomatic from asymptomatic patients. In asymptomatic patients, P. aeruginosa was recovered from gallbladder bile up to 2 mo after endoscopic retrograde cholangiopancreatography. As this P. aeruginosa epidemic was discovered retrospectively because we monitor bile cultures, we advocate this practice as part of endoscopic retrograde cholangiopancreatography procedures.

Role of zinc supplementation in type II diabetes mellitus

Zinc is required for normal immune function and taste acuity and enhances the in vitro effectiveness of insulin. Impaired immune function and taste have been reported in diabetic subjects, and decreased serum zinc levels and hyperzincuria occur in some diabetic subjects and animals. Subjects with type II diabetes were examined to determine whether the similar effects of zinc depletion and diabetes are causally related. Low serum zinc levels were found in 16 of 180 subjects (9 percent). There was no correlation between serum zinc and glycosylated hemoglobin levels. Natural killer cell activity did not differ between diabetic subjects (n = 28) and control subjects (n = 38) and did not correlate with serum zinc levels. T lymphocyte response to phytohemagglutinin was lower in diabetic subjects than in control subjects (70 +/- 10 versus 103 +/- 7 X 10(3) counts per minute) but was not lowest in those with the lowest zinc levels. Taste thresholds for hydrochloric acid, sucrose, sodium chloride, and urea were elevated in diabetic subjects (n = 28) versus control subjects (n = 10), but thresholds did not correlate with glycosylated hemoglobin or serum zinc levels. Zinc supplementation in nine diabetic subjects had no effect on the glycosylated hemoglobin level, natural killer cell activity, or taste thresholds, but it did increase mitogen activity in those with the lowest initial phytohemagglutinin responses. It is concluded that zinc deficiency occurs in a subset of subjects with type II diabetes but is not related to diabetes control and does not explain decreased taste acuity. Zinc deficiency may play a role in abnormal immune function in type II diabetes mellitus.

The monoclonal antibody CJA3 down-regulates the susceptibility of human tumor cell lines to natural cell-mediated cytotoxicity

While developing monoclonal antibodies (MoAb) to colorectal carcinoma (CRC) cells, we noted that one MoAb, termed CJA3, down-regulated natural cell-mediated cytotoxicity (NCMC) against CRC cell lines SW480 and SW620. The MoAb CJA3 was developed by immunizing a BALB/c mouse with fresh human colorectal adenocarcinoma cells. The antigen recognized by the MoAb CJA3 was expressed on several solid tumor cell lines and on one of the six lymphoreticular cell lines tested, but was not detected on normal peripheral blood lymphocytes (PBL). SDS-PAGE analysis of the antigen immunoprecipitated by the MoAb CJA3 from the CRC cell lines SW480 and SW620 and from the melanoma cell line MALME-3M revealed a component with a m.w. of 150,000. Preincubation of CRC cell lines SW480 and SW620 with the MoAb CJA3 for 16 hr reduced their susceptibility to NCMC by about 50%. Kinetic experiments showed that prolongation of the incubation of target cells with the MoAb CJA3 resulted in a time-dependent increase in the amount of MoAb bound. Maximum binding of the MoAb CJA3 was reached after 4 hr of incubation. The increase in antigen expression chronologically paralleled the decrease in NCMC target cell sensitivity, suggesting that the membrane alterations induced by the MoAb CJA3 were important for NCMC against these two cell lines.

The monoclonal antibody CJA3 down-regulates the susceptibility of human tumor cell lines to natural cell-mediated cytotoxicity

While developing monoclonal antibodies (MoAb) to colorectal carcinoma (CRC) cells, we noted that one MoAb, termed CJA3, down-regulated natural cell-mediated cytotoxicity (NCMC) against CRC cell lines SW480 and SW620. The MoAb CJA3 was developed by immunizing a BALB/c mouse with fresh human colorectal adenocarcinoma cells. The antigen recognized by the MoAb CJA3 was expressed on several solid tumor cell lines and on one of the six lymphoreticular cell lines tested, but was not detected on normal peripheral blood lymphocytes (PBL). SDS-PAGE analysis of the antigen immunoprecipitated by the MoAb CJA3 from the CRC cell lines SW480 and SW620 and from the melanoma cell line MALME-3M revealed a component with a m.w. of 150,000. Preincubation of CRC cell lines SW480 and SW620 with the MoAb CJA3 for 16 hr reduced their susceptibility to NCMC by about 50%. Kinetic experiments showed that prolongation of the incubation of target cells with the MoAb CJA3 resulted in a time-dependent increase in the amount of MoAb bound. Maximum binding of the MoAb CJA3 was reached after 4 hr of incubation. The increase in antigen expression chronologically paralleled the decrease in NCMC target cell sensitivity, suggesting that the membrane alterations induced by the MoAb CJA3 were important for NCMC against these two cell lines.

Simultaneous presentation of relapsing Hodgkin's disease and treatment-related non-Hodgkin's lymphoma

A 55-year-old white man was diagnosed in 1975 with Hodgkin's disease stage IIA, mixed cellularity. He was treated with 4,500 rads to an inverted-Y field followed by six cycles of MOPP and remained in complete remission. In 1983 a right axillary lymph node biopsy showed recurrent Hodgkin's disease, mixed cellularity. While receiving his initial chemotherapy he developed persistent epigastric distress. Endoscopic gastric biopsy demonstrated a diffuse large-cell non-Hodgkin's lymphoma. Surface marker studies confirmed the separate identity of these two malignant lymphoproliferative processes. This represents the first reported simultaneous occurrence of relapsing Hodgkin's disease with treatment-related non-Hodgkin's lymphoma.

Peritoneovenous shunt therapy for leaking ascites in the cirrhotic patient

Review of clinical and operative records of 86 patients at the Minneapolis VA Medical Center and Mount Sinai Hospital undergoing peritoneovenous (PV) shunt for intractable ascites revealed a subgroup of patients (n = 9) who developed leaking ascites prior to shunting. The etiology of leaking ascites was as follows: 1) ruptured umbilical hernia ( UH ) (four patients), 2) repeated paracentesis (three patients), and 3) postoperative incisional ascitic fluid leak (two patients). Initial therapy included local sterile compression dressing, intravenous antibiotics, and management of fluid and electrolytes. All nine patients underwent subsequent closure of the fascial defect and PV shunt to prevent reaccumulation of ascites (simultaneous procedures were performed in five patients). No patient developed postoperative septic complications, organ failure, gastrointestinal bleeding, or encephalopathy. There were no early deaths; however, three late deaths (18 months, 2, and 4 years) were due to variceal bleeding and/or liver failure. Ascites was well controlled in seven patients with PV shunt alone, the other two ultimately responding to medical therapy. We conclude that peritoneal fluid leaks can be treated successfully by repairing the fascial defect and placing a PV shunt. In the absence of infected ascites and clinical peritonitis, PV shunt may be performed simultaneously with closure of UH , thus preventing the reaccumulation of ascites during the immediate postoperative period.

Alterations in human natural killer cell activity and monocyte cytotoxicity induced by zinc deficiency

Zinc deficiency alters lymphocyte and monocyte function in man and animals. A patient with isolated zinc deficiency was found to have lymphopenia (420 lymphocytes/microliter), depressed T-cell mitogen response (48% of normal control), increased numbers of circulating T-suppressor cells (OKT8 reactive cells) and decreased circulating T-helper cells (OKT4 reactive cells). Activity of the patient's natural killer (NK) cells was 1 lytic unit/10(6) cells (normal 10 to 40), and monocyte cytotoxicity (MC) was four times that of normal controls. Zinc repletion in vivo improved the peripheral lymphocyte count, corrected the abnormal OKT8-to-OKT4 ratio, normalized T-cell response to mitogen, improved NK function, and lowered MC to control values. A divalent cation chelator, 1,10-orthophenanthroline (OP), was used to simulate zinc deficiency in vitro. T-cells exposed to OP are nonresponsive to mitogen unless zinc is added. NK function of lymphocytes from normal donors exposed to OP was depressed in a time- and dose-dependent manner. NK activity of peripheral blood lymphocytes (PBL) from 12 normal donors exposed to 50 microM OP for 16 hr was 10.3 +/- 7 lytic units/10(6) cells (mean +/- S.E.M.) vs. 32.6 +/- 14 for cells incubated in medium alone. When monocytes were exposed for 16 hr to 50 microM OP, however, MC significantly increased to a range two to five times that of control. OP-induced alterations of lymphocyte and monocyte function was reversed by the addition of 50 microM zinc but not calcium or magnesium. Since NK activity and MC are thought to be important in host tumor immunity, alterations in zinc metabolism may have important implications for human tumor immune surveillance mechanisms.

Zinc and T-lymphocyte function in hemodialysis patients

Thirteen patients maintained on long-term hemodialysis were studied with respect to their serum zinc concentration and T-lymphocyte response to phytohemagglutinin. Six patients demonstrated depression of T-cell mitogen response, while seven patients demonstrated a normal response. The mean serum zinc concentration of the patients with abnormal response was lower than those patients with a normal response (63 +/- 11 versus 75 +/- 14 microgram/di, respectively). There was no significant correlation between an individual's serum zinc concentration and T-cell response (r = 0.16). Five patients whose T-cell responses were depressed were given intravenous zinc chloride during each dialysis run for 6 wk (10 mg intravenous zinc, three times weekly) and were evaluated before and after therapy. All five patients remained anergic to four skin tests antigens. Only one patient (who had the lowest pretreatment serum zinc concentration at 48 micrograms/dl) demonstrated significant improvement in mitogen response after zinc therapy. Although dialysis patients commonly have low serum zinc concentrations and depressed mitogen response, in our patients these two findings were generally unrelated. Additionally, supplemental zinc did not change base-line measurements of T-lymphocyte mitogen response in four of five patients studied.

Scurvy: bilateral lower extremity ecchymoses and paraparesis

A 46-year-old man presented with two weeks of progressive paraparesis and large confluent ecchymoses of both thighs. There was a history of poor dietary intake and daily alcohol use. He had had similar problems each of the past two winters. In 1979 he required hospitalization for "sciatica." In 1980 he was bedridden for two months because of lower extremity weakness. Examination revealed poorly fitting dentures, large confluent ecchymoses of both thighs, perifollicular hemorrhages, and a low serum ascorbic acid concentration. Oral ascorbic acid was begun in the hospital and all clinical symptomatic consequences of scurvy rapidly resolved. We present this case to reiterate the clinical presentation of scurvy and to emphasize the importance of recognizing early signs of nutritional deficiencies that may be confused with more common, but often less treatable, diseases.

Severe zinc deficiency in humans: association with a reversible T-lymphocyte dysfunction

Two patients developed severe zinc deficiency with acrodermatitis during parenteral hyperalimentation. The response of circulating T-lymphocytes to phytohemagglutinin was assessed both during the episode of clinical zinc deficiency and after intravenous zinc supplementation as the sole means of nutritional intervention. Maximum T-cell response to phytohemagglutinin, expressed as percent of simultaneous normal control response, was 2.1% and 27.9% in Patients 1 and 2 respectively. After 20 days of intravenous zinc supplementation (12 mg/d), repeat studies showed the T-cell response of Patient 1 to be 221% of the control, and that of Patient 2 to be 139% of control. In addition, Patient 1 was anergic during the period of zinc deficiency and normally reactive after zinc supplementation. These findings agree with extensive animal studies showing the detrimental effect of zinc deficiency on cellular immunity.

Cytomegalic inclusion disease diagnosed endoscopically

Two patients who received renal transplants developed erosions or ulcers in the upper gastrointestinal tract. In both cases endoscopic evaluation enabled a diagnosis of cytomegalovirus (CMV) infection to be made quickly and safely. We emphasize the importance of early diagnosis of CMV infection and how endoscopy may be helpful.